Wikipedia:Reference desk/Archives/Computing/2011 April 7

= April 7 =

Intel Xeon E7-x870 Processors = Three Identical Models?
Good Morning, fellow RefDeskers! I'm looking at three Intel Xeon E7 Series processors; E7-2870, E7-4870 & E7-8870; and can't find any differences between them. All three of them have the following identical specifications. What is/are the difference(s) between these three processor models? Thanks as always. Rocketshiporion ♫ 00:00, 7 April 2011 (UTC)
 * 2.4GHz Base Clock Speed
 * 2.8GHz Maximum Frequency
 * 10 Cores (20 Threads)
 * 30MB L3 Cache
 * 6.4GT/s System Bus Speed
 * 130W Maximum Thermal Design Power
 * Advanced Encryption Standard - New Instructions
 * Trusted eXecution Technology


 * A good question. According to our List of Intel Xeon microprocessors, the only differences I can see are the spec number, part number, and price. Presumably we've either got it wrong, or there is something we've missed.. Oops! see below...AndyTheGrump (talk) 00:28, 7 April 2011 (UTC)
 * On looking again: "28xx models support single- and dual-processor configurations, 48xx models support up to four-processor configurations, 88xx models support up to eight-processor configurations". AndyTheGrump (talk) 00:30, 7 April 2011 (UTC)


 * (EC) In other words, the various processors in this family differ in their hardware support for cache coherency in a symmetric multiprocessor configuration; probably related to the bus-snooping hardware. Higher-end SMP systems require more sophisticated (and higher-performance) bus-snooping logic to deal with more CPUs. Specific details from Intel: Intel Xeon Processor E7-... Families, and comparative Performance Factsheet, plus ISV quotes and anecdotes for various configurations. Nimur (talk) 00:38, 7 April 2011 (UTC)
 * BTW, are these Xeons using QPI yet? If not, I'd skip the Xeons and go for the "lower-performance" i7 series.  All in all, I'd rather have fast memory and peripherals access, than fast CPU.  Ah, yes, all are Westmere, and all new Xeons are finally using QPI.  Nimur (talk) 00:43, 7 April 2011 (UTC)
 * Did somebody try to use 4 or 8 pieces of e7-2870 in a 4- or 8-socket hardware configuration? Would be interesting to know if the Intel fellows really use three different masks to produce the cpus or if the only differences are name and pricing...

Samsung Champ GT-C3303 Mobile-Phone
i have a Samsung champ camera GT-C3303 mobile. and a brand new computer with GB ram and 2.93 Ghz processor (core2due. with Samsung kies installed in it and i want to connect to internet using my mobile as modem connected with usb cable. i can connect to internet in my mobile but after connecting to PC i cant connect to PC. can u solve my problem thanks.. —Preceding unsigned comment added by 180.215.121.29 (talk) 06:39, 7 April 2011 (UTC)
 * I've seperated your question from the previous one, and added a title. Rocketshiporion ♫ 10:03, 7 April 2011 (UTC)

Wanted: Content management system
Hello. I'm looking for a content management system for my organization's project management. The CMS must allow hosting multiple projects, each of them restricted to users who have been allowed to use the project. The CMS should support sharing of large files (his-res images and videos). Freedom, both in terms of use and cost are appreciated. Any suggestions are welcome. Thank you! 212.68.15.66 (talk) 10:03, 7 April 2011 (UTC)
 * How's WordPress? It's not strictly a blogging platform any more, and if installed/setup properly it should support all the things you listed above. 168.9.120.8 (talk) 11:55, 7 April 2011 (UTC)
 * With a few more requirements I could make a recommendation, maybe some more use cases? Are you looking for a traditional CMS with the capability to run a website, or more along the lines of a Digital Asset Management System?  Or maybe the best qualities of both? As you might expect, Drupal is highly flexible, powerful and cost effective. --rocketrye12talk/contribs 14:32, 7 April 2011 (UTC)

Advice on buying new PC
I'm buying a new PC. I've been advised that, given my requirements (word processing large documents with numerous jpegs), I don't need masses of RAM or hard drive space, but that I should focus on getting one with a fast hard drive and a good graphics card. I've now realized I don't know what this means, and anyway these criteria are often missing from on-line catalogues. What sort of h/d speed should I be looking out for and what sort of graphics card?--Shantavira|feed me 13:39, 7 April 2011 (UTC)
 * Well personally I would think you do need a fair bit of ram for opening and working on large documents with lots images in them. Not excessive amounts, but at least 1GB if you want to have a number of large documents open at the same time, more if you want to multitask with other things. Hard drive speed shouldn't be an issue, any normal hard drive will be fast enough for just opening large documents (I'm guessing ~100MB each, since you didn't specify) and neither should the graphics card. You only need a really good graphics card if you're gaming or working with 3D stuff 82.43.90.38 (talk) 13:57, 7 April 2011 (UTC)
 * Also, the graphics card should be irrelevant for those requirements. The display and processing of large images may take advantage of a graphics card, but I have a hard time imagining the dinkiest integrated graphics card not being good enough.  Paul (Stansifer) 14:14, 7 April 2011 (UTC)
 * The fastest hard drives in a desktop will be 7200 RPM and have a large cache (32 or 64MB most likely). You could also go with an SSD, but that could double the cost of your computer. With your requirements, you'll find that 4GB of RAM, any multicore processor, and a 7200 RPM hard drive will be more than fast enough for what you need with some room to grow. The graphics card isn't important in your requirements, but dedicated graphics won't pull from your CPU and RAM as much as Intel graphics. Look for Radeon, nVidia, and GeForce to signify a dedicated graphics card. If it says "integrated" or "Intel" graphics, and you can get a computer with similar specs for a similar price, go for a dedicated graphics card. It shouldn't matter which one if you don't do any gaming or major 3D or video work. 206.131.39.6 (talk) 16:27, 7 April 2011 (UTC)
 * Most modern operating systems (Ubuntu / GTK; Mac OS X ; Windows, since Vista) - all use the graphics card and GPU extensively during day-to-day operations. Even if you aren't a 3D-gamer or a CAD/engineering user, your GPU and graphics RAM will make a significant contribution to your user experience.  Things like switching windows, maximizing, and even just running at high resolutions, all take advantage of a powerful GPU accelerator.
 * Truthfully, the PC market is segmented along price-points. If you buy a $300 system, it will underperform compared to a $700 system, or a $1500 system.  It is almost impossible to put a high-end CPU in a low-end motherboard; so the "mix-and-match" approach is probably a bit misleading.  Select your price-point, and accept the level of performance that the major system-vendors can provide you at that price.  Then, if you decide you need a little more oomph in your RAM or hard-drive, upgrade (or downgrade) from the base-systems.  You won't turn a $300 system into a competitive match for a $1500 system by swapping out two components, though.
 * A few rules of thumb: more RAM is almost always a good thing. A faster CPU is usually a good thing, but doesn't always make the most noticeable difference.  For hard-drives, all modern drives have huge capacities: so if you want to "upgrade," select a faster hard-drive rather than a larger hard-drive.  (Many portable computers trade down to a 5400rpm drive to save power, but consider bumping back to 7200rpm).  For GPUs, more video RAM is probably a bigger improvement than any other GPU spec (unless you're a 3D gamer).  However, the number of GPGPU-accelerated desktop programs in increasing, so you may find that your paint program or even your word-processor runs faster if you have a CUDA- or OpenCL capable card.  Nimur (talk) 16:46, 7 April 2011 (UTC)
 * They use the graphics card, but they don't necessarily need a fancy one. I have Compiz's wobbly windows, and various other effects enabled on my netbook (the integrated graphics card is an "Intel Mobile 945GME Express", which I doubt is even fancy as integrated graphics cards go).  Antialiasing is turned off, but the framerate is good.  Paul (Stansifer) 17:08, 7 April 2011 (UTC)

The cheapest computer you can find at Best Buy will probably do the trick; will probably have a 2GHz+ dual core processor, 2-3GB+ of RAM, may or may not have a proper graphics card (nvidia or ati [not on the motherboard / intel] — worth the small extra cost). The future is now. ¦ Reisio (talk) 16:40, 7 April 2011 (UTC)
 * Is there any reason you believe a GPU on the motherboard is necessarily lower-performance than one on a breakout card? That's a very old-fashioned mindset from an era when circuit-packaging was still a very difficult task.  Nowadays, even the highest-end GPUs and the fastest video-RAM can be integrated on the mainboard.  And in some system architectures, shared main- and video-RAM yields higher performance than the old-fashioned, dedicated graphics RAM.  (Essentially, a daughter-card forces a NUMA machine architecture, which is inherently lower-performance... again, an old-fashioned engineering tradeoff from the days when packing in 4GB of RAM was impossible).  Nimur (talk) 16:49, 7 April 2011 (UTC)
 * He's not going to open it up (& a clerk at Best Buy wouldn't know :p), and most boxes with nvidia or ati stickers will have separate cards. You're talking about possibilites and I'm talking about cheap computers with three choices: intel, nvidia, ati.  Onboard nvidia beats onboard intel, too. ¦ Reisio (talk) 17:00, 7 April 2011 (UTC)
 * I have to agree with Reisio here. IGPs are crap. Whether this will actually make a difference to the OP is another question but talking about possibilities is a bit pointless when a look in the real world will easily dispel any illusions. In fact while this isn't something I've looked in to a while, I'm pretty sure it remains the case that the crappiest same gen standalone card with limited memory primarily relying on system memory will still outperform the best IGP. It may be things are different with professional cards and systems, this isn't something I've looked in to, but these are expensive and not something the OP is likely to encounter. Note that in laptops the discrete GPU smay or may not be on the same board, however these aren't IGPs and will still communicate over the PCI-express bus and can be basically be thought of as standalone AFAIK. And I've never seen anyone use them in desktop systems anyway because they cost more but perform worse and create additional driver issues. P.S. I'm sure some small form factor PCs do use mobile GPUs, however these are likely to cost more then an equivalent more normal sized system so unless it's actually something the OP wants it's not worth considering. P.P.S. The fusion/APU concepts was supposed to shake things up a bit. Last I heard, this hadn't really happened but it looks like it's now starting to  with the low end discretes starting to lose to high end Intel APU graphics. Probably things will get even more complicated when AMD higher end lines (like Llano) become available since Intel have struggled with GPU performance for so long (a quick search confirms I'm not the only one to think this) and Larrabee (microarchitecture) failed as a GPU but we're not quite there yet. Nil Einne (talk) 17:47, 7 April 2011 (UTC)


 * You don't say where you are, and you don't mention a budget, but if you're in the US, one approach is simply to go to Costco and buy whatever desktop or laptop PC that is within your budget. They have an excellent 90-day return policy if you find the PC is insufficient for your needs.  Currently I think they only stock HP machines, but this may change over time.  I've bought several desktop and laptop PCs there and returned a couple, and will continue to do so because of that return policy.  Comet Tuttle (talk) 18:25, 7 April 2011 (UTC)


 * The lowest end HP is still a good buy, particularly in this age of cheap advanced hardware. ¦ Reisio (talk) 00:15, 11 April 2011 (UTC)

Changing window manager on Fedora 12?
Although I've used Linux for more than a decade now, both in home, university and work settings, I am still not exactly a high Linux guru. So I am writing here on Wikipedia to ask this question. I just found out that as I am running Fedora version 12, I have Compiz installed as default. I'd like to try it instead of the usual MetaCity, but I'm not sure how I would go about it. I first tried to run  directly, and this resulted in a message saying that this screen already has a window manager, and suggested I run   with the   option. However, I didn't want to do that, because I didn't know what would happen if Compiz somehow failed to start up, would I be left without a window manager at all. So I switched to a different screen with Ctrl-Alt-F2, which didn't even have X Windows running. Trying to run Compiz caused an error message about not having an X server, but trying to start an X server caused an error message about already having one (albeit on a different screen). So can anyone give me instructions on how to run Compiz on X Windows without necessarily having it become the default window manager, so I could always have MetaCity to fall back upon? And if Compiz does work OK, how to make it the default window manager? J I P &#124; Talk 18:58, 7 April 2011 (UTC)


 * When you login, there is a session option that you can use to select what window manager you want to use. My experience with Fedora is that Compiz is tied heavily to KDE. The latest version of Fedora with all updates even replaced "KDE" with "KDE-Compiz". -- k a i n a w &trade; 19:07, 7 April 2011 (UTC)
 * I was not able to find such an option on my Gnome login screen. In fact, the login screen presents no information about sessions or window managers whatsoever. There is only an option to switch to a different user, or to change the session language or keyboard layout. J I P  &#124; Talk 19:33, 7 April 2011 (UTC)


 * Please ensure you installed the compiz manager (compiz-manager package) and not just compiz. As I noted, compiz is an add-on for both Gnome and KDE. So, the compiz package is what is needed for all types of compiz, not just the compiz manager. -- k a i n a w &trade; 19:47, 7 April 2011 (UTC)
 * I didn't have compiz-manager installed so I installed it. However, that didn't have any effect on the login screen, it is still presented without any information about sessions or window managers, as if the whole concepts didn't exist. J I P  &#124; Talk 19:59, 7 April 2011 (UTC)
 * In Gnome, Compiz doesn't have to do with sessions. Is there a "Visual Effects" tab in Preferences > Appearance?  Does setting it to "Normal" or "Extra" make things fancier?  Paul (Stansifer) 20:58, 7 April 2011 (UTC)
 * No there is no such tab. There is "Desktop Effects" under Preferences but selecting it only gives an error "Desktop Effects requires hardware 3D support". J I P  &#124; Talk 03:12, 8 April 2011 (UTC)


 * That's it then. The compiz-manager won't run because you don't have hardware 3D support - at least you don't have support recognized by compiz. This can be due to using a driver that doesn't expose the 3D hardware to the operating system. Are you using the manufacturer's driver for your card (and does your card have 3D hardware support)? -- k a i n a w &trade; 12:14, 8 April 2011 (UTC)

OK, so apparently Compiz won't work on my system. But if I decide to try a different window manager, how do I generally go about switching to another window manager? I don't see any option to do it in the Gnome user interface. Do I just run the window manager from a terminal with the  option? How do I know whether the new window manager will stick until I switch to another window manager again, or will revert back to MetaCity when I log out or reboot? J I P &#124; Talk 18:03, 8 April 2011 (UTC)


 * When you have more than one window manager that will work for your system, you are given the option to change window managers in the login screen. -- k a i n a w &trade; 18:13, 8 April 2011 (UTC)

Gmail attachment
Have written an outgoing message. I click on "attach file" and nothing happens. What can I do? I am running Vista & Firefox. Kittybrewster  &#9742;  21:06, 7 April 2011 (UTC)
 * Got it. Closed firefox & restarted it. Kittybrewster  &#9742;  21:40, 7 April 2011 (UTC)

audio
From the history section of the television article it says "by modulating the output signal of his TV camera down to the audio range, he was able to capture the signal on a 10-inch wax audio disc using conventional audio recording technology". What programs could I use on a Windows 7 computer to convert video data into audio, and back? 82.43.90.38 (talk) 22:10, 7 April 2011 (UTC)


 * I call on that.  Video signals are high bandwidth signals: even a crummy monochrome 320x240 @ 24 fps with only 16 gray-scale levels would still be about 1 MHz of data.  There's no way to fit even this terrible quality signal in to the "audio" range, which by definition ranges from 0 to 22 kHz.  Without a digital scheme to lossy-compress that, it'd be impossible to obtain a 20:1 compression without completely garbling the signal.  A proper television signal, with modern digital encoding, occupies something more like 6 MHz of signal bandwidth.  Highly-compressed video can range from ~ 300 kBits/sec, and given a digital encoding, could probably fit into a few hundred kilohertz.  To accomplish such a feat in 1925, using only analog processing, would result in a video signal that would bear essentially no resemblance to the original scene.
 * If you're actually interested in software and/or hardware video signal experimentation, read our amateur television article. HAM radio enthusiasts sometimes encode 100x100 grayscale and have a lot of tricks up their sleeves to squish that into tiny bandwidth - but 20 kHz is essentially impossible.  Nimur (talk) 00:17, 8 April 2011 (UTC)


 * Nimur, you're assuming that the length of the video signal equals that of the audio. Couldn't a minute of video be converted to, say, an hour of audio, and still maintain reasonable quality ? StuRat (talk) 05:51, 8 April 2011 (UTC)


 * Phonovision says he dropped the frame rate to 4 per second. Converting video to slower audio implies some kind of video recording device as a component of the system, and a video recording device is all we're trying to invent here. Instead of dropping the frame rate, he could have recorded each line of image separately onto 30 discs. If the resulting recording was rearranged so that each disc contained a series of complete frames, that would be like you suggest. Then the recording would have to be played back at high speed (about 500 rpm?) and discs changed about twice a minute. Might as well keep the parallel format, I think. 81.131.37.40 (talk) 06:53, 8 April 2011 (UTC)


 * Phonovision also says that this guy invented "Noctovision" and a balloon-powered shoe. I'm still of the opinion that packing reasonable-quality, watchable video into 20 kHz would be essentially a technical impossibility using modern technology, let alone pre-digital techniques.  For perspective, read the history section at Slow-scan television, which I think is a bit more reliable. Nimur (talk) 12:55, 8 April 2011 (UTC)


 * The mention of those two inventions don't mean the article is unreliable. It doesn't claim noctovision was any good for anything, and the shoe was not balloon-powered by balloon-padded, a logical development from the pneumatic tyre, much like Nike Air Max. Besides, the phonovision article says "the results were considered a failure at the time", so yeah, I guess they weren't reasonable quality or watchable, but they were still video recorded as sound. "Baird had to make a number of compromises to get the process to work", says the article, and "the limitations of the discs makes the recovered imagery fall far short of the original studio quality", says the source. Do you think 30-scan-lines, 4 frames per second, monochrome recording onto a 78 (or faster?) is merely crappy - which isn't disputed - or are you saying it would be so bad that it qualifies as impossible? Which would mean hardly any images could be recognized, motion couldn't even be guessed at ... no, I don't think it can have been so bad that it didn't deserve the name "video". 213.122.53.188 (talk) 14:18, 8 April 2011 (UTC)


 * Just like "who invented the airplane," the similar question "who invented television" is plagued by long disputes over technical details and definitions (not to mention nationalistic fervor and propaganda-style hero-ization of key individuals). It's fair to say that Baird invented something - and certainly worked on image and video technology.  It's also fair to say he was "ahead of his contemporaries" and may even have laid down the framework for future innovation.  But I'm very reluctant to say he "invented television" or even that his engineering work contributed to or influenced any of the later developments at RCA or Bell Labs (institutions, rather than individuals, who really have earned the accolade "inventor of television."  This marked shift from lone-genius to institutional inventor is a hallmark of 20th-century technological complexity).  Anyway, as I re-read the original question, it seems that our OP is less interested in how somebody would do this in 1925 with Baird's technology, but is more interested in how to use modern technology for video-to-audio conversion.  See below for my ideas.  Nimur (talk) 16:34, 8 April 2011 (UTC)
 * The Pixelvision camera from the era before cheap real camcorders recorded video on sped-up audio cassettes. 75.57.242.120 (talk) 08:49, 8 April 2011 (UTC)


 * Back to the original question: it really depends on what you mean by "converting" video into audio. You can play any random file as a PCM audio, and reciprocally, you can convert any recorded waveform into a stream of bits.  Audacity is a software program that can help you play arbitrary waveforms out of your speaker.  If your intent is to effectively convert between video and audio, you should learn a lot about signal processing - particularly, digital signal processing.  This is a complex and subtle field. It's non-trivial to describe all but the most basic video technologies; modern video uses color-space conversion, chroma subsampling, interframe coding, intraframe coding, and lossy compression, so if you want to record a sound and turn it in to a playable video file, you'll need to know intricate details of each of these concepts.  If you just want to muck around with raw video and audio buffers, I recommend playing in MATLAB or GNU Octave, which will help bring you up to speed on DSP for imaging and audio.  Nimur (talk) 13:16, 8 April 2011 (UTC)

Horizontal scrolling with scroll wheel on USB mouse in Windows XP
I would like to continue using the scroll wheel for vertical scrolling and for zooming (CTRL + ), but in addition I would like to scroll horizontally. (I want to use it in Adobe Reader, Firefox, InternetExplorer and in open file system folders).Is this possible in WindowsXP ?46.15.58.17 (talk) 22:47, 7 April 2011 (UTC)


 * Have you tried it? Do you have the latest driver from the vendor? ---— Gadget850 (Ed)  talk 23:19, 7 April 2011 (UTC)


 * Have I tried what ? (I am relatively "computer illiterate" so please explain!) I bought an optical mouse, yesterday, and plugged it in. It works for vertical scrolling, but I have no idea what keys to press (or what ever to do) to make it scroll horizontally ?:-)On the mouse it says: Model no.:HM5211How do I find out who made it (and find their website address? to check whether or not I have the latest driver from the vendor? 46.15.58.17 (talk) 23:51, 7 April 2011 (UTC)


 * My Logitech mouse has a scroll wheel that will also click left and right for horizontal scrolling. ---— Gadget850 (Ed)  talk 00:00, 8 April 2011 (UTC)


 * I see! No, my scroll wheel, unfortunately, does not tilt sideways. 46.15.58.17 (talk) 00:07, 8 April 2011 (UTC)


 * Did a quick search, but don't find a HM5211. What brand is it? If you go to Control Panel → Mouse is there a selection for horizontal scrolling? ---— Gadget850 (Ed)  talk 00:19, 8 April 2011 (UTC)


 * There is no brand name printed on the mouse (Just the name of the store where I bought it). Opening: Control pannel -> Mouse properties. I find no selection for horizontal scrolling. Then clicking the "hardware" tab, shows an entry for "PS/2 compatible mouse" and one for "HID compatible mouse". Neither of them mentions anything about horizontal scrolling and both of the drivers are dated 2001 and supplied by Microsoft. I do not know, nor how to find out, which driver my new mouse actually uses... 46.15.58.17 (talk) 00:46, 8 April 2011 (UTC)


 * What happens if you hold and use the scroll wheel?  ---—  Gadget850 (Ed)  talk 13:06, 8 April 2011 (UTC)


 * You can figure out which driver it uses by looking at how the mouse plugs into the computer. If it's a rectangular connector, it's a USB mouse using the HID driver.  If it's a round or U-shaped connector, it's a PS/2 mouse using the PS/2 driver.  Either way, it sounds like you've got a generic mouse made by the lowest bidder, using Microsoft's standard mouse driver. --Carnildo (talk) 00:04, 9 April 2011 (UTC)